Woxor wrote:I just realized that one of my profs last year had an Erdos number of 2. I had the opportunity to proofread a book he was writing (and be credited in the published version for as much), but I didn't do it! Curses! I don't know how close I'll get to a 3 again.

I thought it was a lifetime thing--if you publish seven papers that would get you a 6, and one that would get you a 3, you still get the 3.

Woxor wrote:I just realized that one of my profs last year had an Erdos number of 2. I had the opportunity to proofread a book he was writing (and be credited in the published version for as much), but I didn't do it! Curses! I don't know how close I'll get to a 3 again.

I thought it was a lifetime thing--if you publish seven papers that would get you a 6, and one that would get you a 3, you still get the 3.

But he didn't actually publish with the professor, so he missed out on the chance to get a 3.

Woxor wrote:I just realized that one of my profs last year had an Erdos number of 2. I had the opportunity to proofread a book he was writing (and be credited in the published version for as much), but I didn't do it! Curses! I don't know how close I'll get to a 3 again.

I thought it was a lifetime thing--if you publish seven papers that would get you a 6, and one that would get you a 3, you still get the 3.

But he didn't actually publish with the professor, so he missed out on the chance to get a 3.

If y'all like, I'll show you this technical report I'm working up, too... it's a (really simple) example of an NP-completeness reduction. That, apparently, would've saved my current adviser and a student of his about a month's work on a particular project, had they caught it then.

As an undergrad, I was published in an undergrad journal.
Chaos, The Pentagon, Volume 63, No. 2, 17-24.

The paper had no co-author, but my professor that was overseeing the paper has en Erdos number of (at leakst) 5. Does that mean I have an Erdos number of 6?, or because he wasn't a co-author my number is still undefined?

the keeper wrote:Does that mean I have an Erdos number of 6?, or because he wasn't a co-author my number is still undefined?

Still undefined. The AMS website has an Erdos-calculator, but it looks at only a small set of magazines (e.g. Phys Rev Letters not included after a certain year) that are "hardcore maths" --- giving strange results where some of my definitely more mathematical friends score undefined/infinite where very biological ones have 3 and 4.
Your supervisor having 5 is relatively high... he might have a lower one in an unexpected way.

@StigHemmer: it gives you 3, not 4! The MathSciNet says so!

I note that however few co-authors I have, I'm 5 in 4 different ways (and 4 in one way)... that is, recognized by the AMS calculator only.
Edit: hm, I'm not 4 because that was a chapter in a book --- the chapter is not jointly written, I had counted myself as co-author of the editors.

not being a math student, i have not authored or co-authored any math papers, and thus don't have an erdos number. but i have something cooler:

that's erdos on the paddle. to the left is my father. this picture was taken in 1980 by my mother, before i was even born. i've met erdos on a number of occasions, but i was really too young to remember now. i'm not totally sure what my father's erdos number is, but i could ask. i know at least one person with an erdos number of +1 (bolobas) was on my father's thesis committee.

edit: my father reports that his erdos number is 2, a few different ways.

zenten wrote:I've slept with someone who put up Erdős for a few weeks at her home, does that count?

Only if she slept with Erdos first, in which case you get an automatic Erdos number of 2. Possibly.

Interestingly, by defining Erdos numbers in this way (and ignoring homosexual relationships, I guess) you would ensure that anyone with an odd Erdos number was female and anyone with an even Erdos number was male. Hmm.

zenten wrote:I've slept with someone who put up Erdős for a few weeks at her home, does that count?

Only if she slept with Erdos first, in which case you get an automatic Erdos number of 2. Possibly.

I never asked her explicitly, but from her description of the guy I would have to say she didn't. Unless she was bitter about the breakup or something.

I was under the impression from 'The Man who Loved only Numbers' that he had a physical problem with his penis, which caused him great pain when he had an erection, and he told someone (can't remember the exact person) that he hadn't had sex (and that was when he was 70)

zenten wrote:I've slept with someone who put up Erdős for a few weeks at her home, does that count?

Only if she slept with Erdos first, in which case you get an automatic Erdos number of 2. Possibly.

Interestingly, by defining Erdos numbers in this way (and ignoring homosexual relationships, I guess) you would ensure that anyone with an odd Erdos number was female and anyone with an even Erdos number was male. Hmm.

Is it bad that I thought of the exact same thing when reading that post? Too bad I'm an undergrad one of my profs I'm pretty sure has an erdos number of 2.

Erdős number 3 in three ways; Erdős number 2 pending. (Technically--but it's really more of a fourth route to 3, since we collaborated only by way of a third coauthor, and have never actually met.) In the stricter sense, where only two-author papers count, it's still infinite.

zenten wrote:I've slept with someone who put up Erdős for a few weeks at her home, does that count?

Only if she slept with Erdos first, in which case you get an automatic Erdos number of 2. Possibly.

Interestingly, by defining Erdos numbers in this way (and ignoring homosexual relationships, I guess) you would ensure that anyone with an odd Erdos number was female and anyone with an even Erdos number was male. Hmm.

There's a CS professor at my school (I don't remember his name (I'm a physics major and have only heard about him through CS majors), and even if I did, probably wouldn't post it) who apparently has slept with many of his Grad Students. My friends and I decided there should be a (his name) number, except you get it through sleeping with people. We know several people with numbers of 2.

Ten is approximately infinity (It's very large)Ten is approximately zero (It's very small)

I'm long out of mathematics. (Never quite finished my PhD.) But my official Erdos number is 3. My unofficial one is 2. The difference is because the official count does not include shared math monthly problems. I have 2 math papers and the aforementioned math monthly problem.

If X doesn't have a topology on it, the basis is probably a Hamel basis, meaning you need to be able to form arbitrary elements of the vector space using only finite linear combinations of basis elements. So there's certainly a basis for the vector space containing each of those functions, but if X is infinite they don't span the vector space, because finite linear combinations of them are nonzero at only finitely many points.

Owehn wrote:If X doesn't have a topology on it, the basis is probably a Hamel basis, meaning you need to be able to form arbitrary elements of the vector space using only finite linear combinations of basis elements. So there's certainly a basis for the vector space containing each of those functions, but if X is infinite they don't span the vector space, because finite linear combinations of them are nonzero at only finitely many points.

Exactly right.

I don't remember the details of the proof, but the answer is that the basis has the same cardinality as the power set of X.

I have a professor who has a problem he hasn't solved yet, but which he discussed heavily with Erdos at some point. Should he solve it and write it up (hopefully with my co-authorship), I believe he'd include Erdos as well, which would get me a 'posthumous' Erdos number of 1 or 2 (depending whether I co-author the paper). Much speculation though.

3.14159265... wrote:What about quantization? we DO live in a integer world?

Having looked up this "Erdos number" and "h-index", I am suddenly intrigued. I'd never heard of ways of ranking scientists. The h-index seems to be more useful than the Erdos number. But having little experience in the world of authorships and co-authorships, I wouldn't really know.

More interestingly, I recently developed something that will probably turn into a math paper in the near future. "The near future" being defined as "when I learn how to do proofs". Speaking of which, if anyone has a goodly amount of experience in this proof business, I may be interested in speaking to you. The math is pretty simple multivariable calculus, but I work math in a very intuitive way and therefore have no idea how to go about proving something that I'm 99% sure is true.

We submitted this to CRYPTO 2008. Sadly, it's not as pure-math as I'd like it to be, but it wasn't all systems-oriented either, and the project itself was a lot of fun anyway. We've implemented hashing, and we just have to tidy up the program a bit more and make it usable.